WASHINGTON (CNN) -- Maybe it was the midday start time. Maybe it was the holiday season. But Wednesday's Republican presidential debate lacked the brutal street-fighting tone that has characterized previous meetings, as well as the past few days on the trail in Iowa.

With the first-in-the-nation Iowa caucuses roughly three weeks away, it was the moderator, and not the candidates who came under fire at this last Republican debate.

Former Sen. Fred Thompson rebelled against debate guidelines laid out by Des Moines Register Editor Carolyn Washburn -- and his campaign kept up the assault after the debate, taking aim at his fellow candidates for not being more openly defiant.

"I am not sure how these other candidates plan to defeat al Qaeda when they can't even take on Carolyn Washburn. The format of this debate was more of a joke than a Mike Huckabee foreign policy answer," said Thompson spokesman Todd Harris in a statement.

Meanwhile, Sen. Hillary Clinton, who has been a top target in most of the recent GOP debates, didn't rate a single mention -- that distinction went to the nation's tax system, as each of the candidates pledged to slash taxes and government spending.

Mike Huckabee, the former governor of Arkansas, had come into the afternoon with a bullseye on his back, thanks to skyrocketing poll numbers that have vaulted him to the top of the field in the Hawkeye State. The last time the candidates met, Huckabee's poll numbers in Iowa were hovering in Ron Paul territory.

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But it took an hour for anyone to seriously take aim at Huckabee, who escaped with a handful of swipes from Romney and Tom Tancredo.

There were "a little less fireworks than I anticipated," a relieved-looking Huckabee told CNN after the debate. "I expected there would be blood on the floor, most of it mine. But I came out of it without a band-aid."

Most of the major candidates seemed a bit tentative, and slightly thrown by the unwieldy debate format. Giuliani, whose recent schedule has been light on events in Iowa, seemed especially subdued. The Giuliani campaign will tell you it is not all about Iowa, where he trails Huckabee and Romney -- they will make their stand in later contests including "Super Tuesday" on February 5.

Romney seemed more at ease. But anything less than a dominant performance may not be enough at this point. Polling may not be an exact science in Iowa; still, the social conservatives that once formed his base here are clearly defecting to Huckabee's campaign.

The man on stage who provided the biggest fireworks was perennial candidate Alan Keyes. The former ambassador and three-time presidential contender tangled with Washburn, injecting himself into exchange after exchange.

In fact, much of the GOP debate seemed to belong to second-tier candidates like Duncan Hunter, Tancredo, Paul and Keyes. That scenario won't play out Thursday -- underdogs Dennis Kucinich and Mike Gravel have not been included in the Democratic debate.E-mail to a friend